Dietitians Dish: Increase in fiber can reduce risk of diverticulosis

By Stephanie Whitley
May 20, 2014 at 12:20 a.m.

Diverticular disease is an increasing problem in the American population. In the 1920s, only 5 to 10 percent of the population had diverticular disease. About 33 percent of Americans by age 50, 50 percent by age 60 and 66 percent by age 80 develop diverticular disease.

All over the world, as countries become more industrialized, rates of diverticular disease increase. There are three major factors that affect the risk of developing diverticular disease: obesity, age and fiber intake. Before we dive into these, let's define diverticular disease.

When there is a herniation in the intestinal wall, this is called a diverticulum. When there are multiple diverticula, you are considered to have diverticular disease. If one of these diverticula becomes inflamed or infected, this is called diverticulitis.

This can be a very serious condition, and symptoms range from nausea or bloating to needing surgical interventions for a bowel obstruction and antibiotic therapy.

Obesity - a body mass index of 30 or greater - plays into the development of diverticular disease because the presence of adipose cells (fat cells) causes chronic, low-grade inflammation. Having a larger waist circumference and waist-to-hip ratio increases your risk even more because adipose cells around your organs are more active.

Getting older can also increase your risk of developing diverticulosis because you have an increase of collagen in your colonic wall and reduced strength of the intestinal wall increasing the risk for herniation. These factors also slow down the motility rate, which increases intestinal pressure and can cause extra straining because of more water reabsorption and harder feces. Long-term use of laxatives and having Irritable Bowel Syndrome also increases the risk of developing diverticulosis.

Finally, fiber intake plays into diverticular disease. The fiber theory is that the more fiber one consumes, the faster motility time of feces, the less water reabsorption in the colon and a reduced intestinal pressure. This results in less straining and more frequent bowel movements.

The big picture is that reduced intestinal pressure reduces your risk for herniation. Studies have found that if you don't have diverticular disease, an extra high diet of fiber will not help you prevent diverticular disease. However, if you have had an episode of diverticulitis, a short-term, low-fiber diet (10-15 grams daily) and then a high-fiber diet once diverticulitis has resolved (up to 28 grams daily for women and 35 grams daily for men) is beneficial.

Fiber is the indigestible carbohydrate found in plants. Therefore, a diet rich in whole grains and produce will not only help those suffering from diverticular disease but also provide added health benefits for those without diverticular disease because of the nutrient rich nature of these foods.

The goal is to make at least half of your grains whole and to consume at least five servings of fruits and vegetables daily. In the past, people with diverticular disease were told to avoid nuts, seeds and popcorn; however, research shows this does not affect the reoccurrence of diverticulitis, and these foods can be safely consumed by all.

In addition, remember to be physically active and to drink more water as you increase your fiber intake.